Electric heating apparatus



O. A. COLBY.

ELECTRIC HEATING APPARATUS.

APPLICATION FILED SEPT. 2I. I9I6.

1 ,332,029 Patented Feb. 24, 1920.

WITNESSES INVENTOR I 0/4 A Co/by v BY I 6W I I I v ATTORNEY UNITED STATES PATENT ORA A. COLBY, OF LARIMER, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

ELECTRIC HEATING APPARATUS.

Specification of Letters Patent. Patented Ebb, 24t 192%,

Application filed September 21, 1916. Serial No.121,428.

To all whom it may concern."

Be it known that I, ORA A. COLBY, a citizen of the United States, and a resident of .Larimer, in the county of Westmoreland and State of Pennsylvania, have inventeda new and useful Improvement in Electric Heating Apparatus, of which the following is a specification.

My invention relates to electric heating apparatus suchas air heaters,'oven heaters and other devices in which the resistance conductors are exposed to the air, and it has for its object to provide an electric heater of the above-indicated character which shall be simple and inexpensive in construction and in which the resistance conductor shall be arranged in a novel manner in order to increase the efficiency and the effective life of the apparatus.

In the accompanying drawing, Figure l is a side elevational view, with parts shown in section, of an electric air heater constructed in accordance with my invention, and Fig. 2 is an end elevational view with parts broken away and shown in section, of the structure shown in Fig. 1. j

The heating device shown in the drawing comprises a sheet-metal frame supported upon legs 1 and consisting of top and bottom plates 2 and 3 and sides 4: and 5, which together form a box-like structure open at the front and rear. Supported centrally and vertically within the-frame is a partition formed of one or more sheets 6 of asbestos lumber or other suitable insulating material. The sheets! 6 are fastened in place, as shown, by means of parallel horizontal rods 7 and 8 which extend lengthwise of the heater and to which: the upper and. lower edges of the sheet 6 are attached by means of suitable fasteners 9.

The vertical insulating partition is provided with perforations arranged in four rows 10, 11, 12 and 13, through which a resistance coil 14 is passed in a series of zigzag sections. It will be observed that the rows of perforations are staggered so as to 4 bring the two zig-zag resistance sections in each half of the device into staggered parallel relation. It will also be observed that half of the straight portions of each resistance section are disposed on one side of the insulating sheet 6 and the other half on the other side and that the adjacent parallel portions of the two sections are disposed on opposite sides of the insulating sheet and are thereby maintained out of direct comfmunication and prevented from heating one another by mutual radiation. It will be noted that the rising air current 1n the? lmmediate vicinity of the heating coils travels upwardly alongthe insulation sheet 6 and passes over a single heating conductor in its course. The stream of heated air, leaving a lower, zigzag section of heating coil 14, passes up between the two adjacent upper sections without loss of heat heating power and overheating of the resist ance conductors which materially shortens their effective life. w

The several resistance coils may be connected and supplied with current in any suitto either of these upper sections which are able manner. As shown, connection to line conductors is made by means of conductors 15 and lfi which extendfin a cord 17,

" through a bushing 18 in the rear wall of the device. The conductors 15and 16 are led to a snap switch 19-which may be of any suitable construction and is centrally disposed at the front of the heater. One of the terminals of the snap switch 19 is connected. by.

means of conductors 20 and 21, to binding screws 22 and 23 at opposite ends of the insulating sheet 6, these binding screws also serving to connect the four sections of resistance conductors in two parallel groups. The inner or central ends of the four resistance coils are connected toterminals 27 and 24, which are, in turn. connected, by means of conductors 25 and 26,110 another terminal of the snap switch 19.

' It is obvious that the switch 19 may be arranged to energize either a part or all of the resistance coils and that the several coils either in series or in parallel relation. It

will also be understood that various structural modifications may be efiected in the apparatus which I have shown and described without exceeding the limits of my invention or the scope of'the appended claims.

I claim as my invention:

1. An electric air heating device comprising a plurality of zig-zag sections of resistance material exposed to the air and arranged vertically with their several bent portions substantially parallel, and means for maintaining the vertically adjacent parallel portions of the said sections out of direct communication, so that the rising column of air will be heated but once in passing two sections,

2. An electric air heating device comprising a perforated sheet of insulating material arranged in a vertical plane. and a resistance conductor extending, in zig-zag ar rangement, through the perforations in the said sheet in such manner that the contiguous portions in a horizontal direction lie on opposite sides of said perforated sheet, so that the rising column of air will be heated but once in passing two sections.

3. An electric air heating device comprising a frame, a perforated sheet of insulating material supported vertically thereby, and a resistance conductor extending, in zig-zag arrangement, through the perforations in the said insulating sheet in such manner that the contiguous portions in a horizontal direction lie on. opposite sides of said perforated sheet, so that the rising column of air will be heated but once in passing two sections. 4

, 4. An electric air heating device compris-- conductor being disposed on opposite sides of the 'said insulating sheet in a mariner to v prevent mutual radiation therebetween, so that the rising column of air will be heated but once in passing two sections.

5. An electric heating device comprising a vertically disposed sheet of insulating material carrying two resistance conductors ex z1gzag formation in a horizontal tending 1n direction upon the sheet and so arranged,

qne above the other, that the vertically correspondmg portions lie on opposite sides of said sheet of insulating material.

In testimony whereof, I have hereunto subscribed my name this 7th day of Sept, 1916.

()RA A. COLBY. 

